Self-sealing valves for multiwall bags



Nov. 27, 1962 J. w. MEANS ETAL SELF-SEALING VALVES FOR MULTIWALL BAGS 2Sheets-Sheet 1 Filed Jan. 16, 1961 JOHN W. MEANS KENNETH L. MOOREATTORNEY Nov. 27, 1962 J. w. MEANS ETAL SELF-SEALING VALVES FORMULTIWALL BAGS 2 Sheets-Sheet 2 Filed Jan. 16, 1961 INVENTORS JOHN W.MEA N6 KENNETH L. Moo/25' United States Patent M 3,065,899 SELF-SEALINGVALVES FOR MULTIWALL BAGS John W. Means, Cleveland Heights, Ohio, andKenneth L. Moore, East Aurora, N.Y., assignors to Chase Bag Company, acorporation of Delaware Filed Jan. 16, 1961, Ser. No. 82,907 Claims.(Cl. 229-625) The present invention relates to self-sealing valves formulti-wall bags and it consists in the combinations, constructions andarrangements of parts herein described and claimed. 1

Generally there is provided a shipping bag formed of two or more plys ofpaper or other relatively non-elastic sheet material, the bag beingclosed at its upper and lower ends either by folding the upper and lowerportions of the front and rear walls of the bag toward each other inoverlapping arrangement with the inturned portions pasted or otherwiseadhered to each other, or by bringing the upper and lower portions ofthe front and rear walls together, folding a length of tape over saidedges and then joining the edges and the tape by sewing in conventionalmanner. A filling opening is formed by inwardly and downwardly foldingthe upper portion of an end wall of the bag in such manner as to definean inwardly and horizontally disposed sleeve-like portion into which afilling nozzle can be inserted, in known manner. The novelty of thepresent disclosure resides primarily in the provision of a tubularextension of the filling portion of the bag, said extension beingpreferably constituted by a section of a relatively thin polyethylenetube, thermoplastically welded or adhesively secured at its outer end tothe inner margin of the filling opening. The sleeve is desirably slitlongitudinally at its lower inner end to facilitate the introduction offluent material into the bag.

The sleeve formed of a section of polyethylene tube is best employedwith a bag of the pasted-end type. However, in a bag of the sewn-endtype, the sleeve may conveniently be formed of a piece of polyethylenejoined by an adhesive or by thermoplastic welding along one edge to apiece of paper, which piece of paper can be inserted between theinturned edges of the bag plys defining the lower portion of the fillingopening. The pieces of paper and attached polyethylene are. then foldedupwardly about their common midline and their upper edges are caught inand sewed into the upper bag closing seam.

Self-sealing valves of the prior art have usually been made of paper,which to provide the necessary strength, has necessarily been somewhatstiff, resulting in an unreliable closing and an often ineffective sealafter closing.

It is accordingly a principal object of the invention to provide aself-sealing valve for bags of the type disclosed, which is both highlyreliable in closing and highly effective in producing a leakproof seal,due to the extreme flexibility of the relatively thin polyethylene sheetmaterial which readily folds over on itself or crumples up upon slightback pressure from the contents of the filled bag.

It is another object to provide a self-sealing valve which can be simplyand economically formed from a section of polyethylene tubing.

It is a further object to provide a self-sealing valve for multi-wallbags, in which the valve element comprises a piece of sheet plasticadhered to a piece of paper, whereby the paper portion produces ananchoring and attaching base for facilitating insertion and joining ofthe valve to the bag filling opening.

It also is an object to provide a device of the character set forthwhich is simple in construction, inexpensive to manufacture and yeteffective and elficient in use.

Other and further objects of the invention will become 3,065,899Patented Nov. 27, 1962 apparent from a reading of the followingspecification taken in conjunction with the drawings, in which:

FIGURE 1 is a fragmentary perspective view of a preferred embodiment ofthe invention,

FIGURE 2. is a front elevational view partly broken away, of the showingof FIGURE 1,

FIGURE 3 is a perspective view of the disclosure of FIGURES 1 and 2immediately prior to closing the upper end of the bag by sewing,

FIGURE 4 is a perspective View showing the assembling step preceding thefolding illustrated in FIGURE 3,

FIGURE 5 is a perspective view of the valve element,

FIGURE 6 is a perspective View of the valve element of FIGURE 5 explodedto show its component parts,

FIGURE 7 is a perspective view showing the valve element with its partsin their relative functional positions,

FIGURE 8 is a perspective View of a modified form of valve element,

FIGURE 9 is a fragmentary perspective view of a pasted bag incorporatingthe valve element of FIGURE 8, and

FIGURE 10 is a view similar to FIGURE 9 but showing the valve in closedor sealing condition after the filling of the bag.

With reference now to FIGURES 1 through 7 of the drawings, the numeral10 generally designates a shipping bag of the type commonly used forshipping Portland cement or other similar comminuted materials. Bag 10is herein disclosed as comprising four plys of paper 11 through 14, saidbag having a front wall 15, a rear Wall 16 and a pair of side walls 17(only one of which is herein disclosed). The side walls 17 are mediallycreased at 18 to define a gusset so that the side walls can be infoldedas partially indicated in FIGURE 3 to permit collapsing of the bag 10for space saving during shipping or storage of the empty bags.

The upper portion of the side walls 17 is also horizontally creased at19 so that the portions 20 and 21 of the side wall 17 can be foldedinwardly and downwardly (as best seen in FIGURES 2 and 3) to constitutethe nozzle receiving portion of the valve hereinafter more fullydescribed.

The valve member proper is disclosed best in FIG- URES 5 and 6. A sheetof polyethylene plastic material of a thickness of one to two mils, withone and one-half mils having been found suitable for most uses, isdesignated by the numeral 22. Sheet 22 is adhered along its outer margin23 in FIGURE 2, or lower margin in FIG- URES 5 and 6 by thermoplasticwelding or by the use of a suitable adhesive, to the longer base of thetrapezoidal piece of paper 24. The piece of paper 24 serves as ahandling and attaching element for the valve member, being insertablebetween the plys constituting the small panels 20 and 21 by which it istemporarily held against displacement as the top of the bag is closedinto the positions of the panels shown in FIGURE 1. Thereafter the upperedges of the front and rear panels 15 and 16 and the upper extremitiesof the inturned panels 20 and 21 are embraced by a closing and sealingstrip 25, the assemblage being completed by sewing to produce thestitches indicated at 26. Prior to assembly the valve element 22 isdesirably slit at 27 to facilitate the filling operation.

In the species of FIGURES 8 through -10, the numeral 30 generallydesignates a bag of the pasted closure type. Bag 30 is likewise formedof a plurality of plys of paper or similar sheet material, and has itsrear wall 32 folded forwardly and downwardly at its upper end and itsfront wall 31 folded rearwardly and downwardly to overlap the margin ofthe forwardly extending portion of the rear wall 32 along the pastedseam indicated at 33.

The end wall 34- is creased at 35 to form an infolding 1:3 gusset forfiat packing of the empty bag and with further fold lines 36 and 37 todefine the downwardly and inwardly folding panels 38 and 39, which wheninfolded define the floor and side walls of the nozzle receiving portionof the filling valve next to be described.

The valve element proper is. a sleeve 49 (FIG. 8) which may convenientlybe cut from a continuous tube of 1 to 2 mil polyethylene plastic. Thesection 40 is inserted into the nozzle receiving opening formed by thepanels 38 and 39 and the overlying inturned upper end edges of the frontand rear panels 31 and 32. The inserted sleeve 49 is thermoplasticallywelded or adhesively secured in place, as along the adherence line 41,with the unattached end 42 of sleeve extending well beyond the innermargin of the nozzle receiving portion of the bag. Sleeve 40 is alsodesirably slit longitudinally along the free lower portion thereof tofacilitate filling of the bag.

While but certain. forms of the invention have been shown and describedherein, it will be readily apparent to those skilled inthe art that manyminor modifications may be made without departing from the spirit of theinvention or the scope of the appended claims.

What is claimed is:

1. In a bag formed of at least two plies of relatively non-elastic andsomewhat stiff sheet material and having the upper and lower endsthereof closed by permanently joined forwardly and rearwardly turnedupper and lower portions of the front and rear walls respectively ofsaid bag, said bag having a horizontally extending sleeve-like fillingportion at an upper corner thereof defined by a downwardly and inwardlyfolded upper portion of a side wall and the overlying bag-closing upperportions of the front and rear walls, the improvement comprising: asleeve attached to said sleeve-like portion and constituting an inwardlyoriented extension thereof, whereby said sleeve will readily crumple upor fold over upon itself from slight back pressures from the bag fillingfluent material to provide an effective and reliable bag sealing valve,said sleeve being a piece of highly flexible tough sheet material fixedadjacent its outer edge to a piece of somewhat stiff sheet material witha major portion of said flexible sheet projecting inwardly of said stiffsheet material and constituting the entire inner end portion of saidsleeve, said pieces being folded upwardly about a common mid-line, andsaid piece of relatively stiff material being substantially entirelyinserted between plys of the portions of said bag defining saidsleeve-like filling portion.

2. Structure according to claim 1, said sleeve being provided with aslit in its lower inner portion to facilitate filling of said bag.

3. Structure according to claim 1, said sleeve being formed ofamoisture-resistant material thereby to protect hygroscopic fillingsubstances.

4. Structure according to claim 1, said material being polyethylene.

5. Structure according to claim 4, wherein the upper margins ofsaid-pieces-are sewn into a seam by which the upper end of said bag isclosed.

References Cited inthe file of this patent UNITED STATES PATENTS2,177,122 Tooker Oct. 24, 1939 2,359,033 Gootwald Sept. 26, 19442,590,568 Peters Mar. 25, 1952 2,751,142 Williams June 19, 19562,865,556 Williams Dec. 23, 1958

